Continuous method of applying glass spheres or particles to flat surfaces



April 16, 1935. J. D. M BURNEY ET AL I 1,998,053

CONTINUOUS METHOD OF APPLYING GLASS SPHER'ES QR PARTICLES '10 FLAT SURFACES Original Filed Nov. 8, 1930 m I N lo 1 N o w o N m----6 H o c&

- Do ran M Bz/rney, Edgar lYo/lau, lnventors Patented Apr. 16, 1935 UNITED STATES PATENT OFFICE CONTHWUOUS METHOD OF APPLYING GLASS SPHERES OR PARTICLES TO FLAT SUR- FACES poration of Delaware Application November 8, 1930, Serial No. 494,392

Renewed June 5, 1934 ICIaim.

This invention relates to the application of glass beads, prisms, rods or finely ground glass to fiat surfaces, and more particularly to an improved process for the application of particles of this character to a continuously moving strip adhesiveto/dry and consequently the application.

of heading is intermittent rather than continuous with an accompanying variation in 'the uniformity of the finished product.

This invention has as an object an improved methodfor applying glass beads or similar particles to'fiat surfaces. Another object is to provide an improved process for the continuous application of, glass beads or similar particles to a continuously moving strip of sheet materia Another object resides in an improved process for applying glass beads or similar particles to sheet material which result in a product having improved optical properties. Anotherobject is an improved process for applying glass beads or similar particles to base material covered with an improved adhesive which results in a better anchorage of the particles on the base material. Another object is an improved process for applying glass beads or similar particles to base material in'the form of a pattern or design. A still further object resides in the mechanism utilized to carry out our improved process. 3

These objects are accomplished by the following preferred .mode of procedure described in connection with the single figure in the drawing which is the side view of the mechanism suitable for carrying out the invention.

The numeral I designates the roll or material,

such as paper or fabric, to which the glass beadsor particles are to be applied. The base material 2 passes over a roller 3 which, together with the roller 4 around which the material passes, serves as a guiding means to direct the material into the adhesive 5 contained in the receptacle 6. After the sheet material 2 passes over the roller 4, it moves in a substantially horizontal plane around a pull roll 1 and over a roller 8 to the windout roll 9, journalled in the support Ill. The rolls 1 and 9 are driven by a motor I I thru a belt l2 as shown, and it is by this means that the sheet material 2 is unrolled from the roll I and drawn thru the mechanism which results in the application of the glass beads or particles to the material. After the sheetmaterial 2 has been dipped into the adhesive 5, by passing around the roller 4, the adhesive is spread and evenly distributed over the material by means of a scraping or doctor 'knife I3, supported by any suitable means (not shown). The doctor knife 'l3 bears against the material 2 between two rollers M. The coated material then passes beneath the receptacle I 5 containing the glass beads or particles l 6 which fall onto the material 2, thru screens, in a regulated manner hereinafter described.

A shelf .or ledge I1 is placed under the material 2 at the place of the application of the particles in order to prevent the material from sagging. The material, with its coating of glass particles, then passes thru a drying chamber l8, carriec! by supports 28 and heated by steam coil IS. The drying chamber is ventilated by means of a fan contained within the housing 20, which is supported by a base 2 I. The fan, driven by a motor 22, draws air from the openings at each end of the machine thru which the material passes, thru the funnel-like portion 25 to the conduit 24, and finally thru the fan outlet 23. As the particle covered material passes around the pullwheel 7, the excess particles are deposited in the pan 21.

The receptacle for the particles l6 has a screen bottom 29, the mesh of which is just suflicient to allow the particles to pass thru. Thescreen 29 slides on a second screen ,30 of substantially the same mesh as the screen 29. The necessary relative motion between the screens 29 and 30 required to permit the passage of particles 16 thru the two screens may be obtained in any desired manner.

In the present embodiment of the invention we have illustrated the screen 30 as the stationary screen having suitable supporting means (not shown) The receptacle I5 is provided with flanges I5 which straddle the frame pieces 3| of the screen 30 and permit the receptacle [5 to be reciprocated over the screen 30.

This screen combination above described may be referred to as a sieve-valve". The deposition of the particles in the manner permitted by this valve contributes materially to thegiccess of the process.

In the case of a number of substances, such as cotton flock or finely ground cork, a single screen is suflicient to support the material when stationary, yet when shaken will permit it to freely pass thru. However, the density of glass is such that beads or finely ground'particles will pass thru a single screen even when stationary, unless the screen is of such fine mesh that the particles cannot be made to pass thru even when vigorously shaken. By employing two screens of the proper mesh, however, this can be controlled since the interstices of the screens are blocked except when one of the screens moves over the other. This motion may either be reciprocating or rotary, and the necessary movement of one screen relative to the other may be effected manually, or the movable screen may be connected to the mechanism for driving the sheet material so as to regulate the quantity of the particles deposited-with respect to the length of the material 2 which passes in a given time underneath receptacle l5. By this means it has been found that a uniform distribution of beads can be applied continuously to a moving base material. It will be understood, however, that either screen may be the movable one, thus the receptacle may be held stationary and the bottom screen 3!! moved in its plane relative to the screen 29.

Several advantages flow from the method of applying the glass particles as above described. In this connection the application of adhesive by the combined use of the dipping roll 4 and the doctor knife I3 is especially advantageous. We have found that the application of the adhesive by the use of a knife alone results in scratches which are very undesirable and furthermore, the

adhesive so applied does not give satisfactory anchorage.

The use of the dipping roll alone results in the desired anchorage, but due to a very slight unevenness of flow the frequent anchorage of more than one thickness of beads produces a very undesirable optical effect, which is especially disadvantageous when the product is used as a mov ing picture screen. By the combination of dipping roll and doctor knife herein disclosed, these disadvantages are overcome and a product having the desired optical properties with the beads firmly anchored is produced in a continuous operation.

The type of adhesive found to give best results in connection with the present process may be described as a cellulose nitrate composition containing a suitable solvent softener. The practical operating limits of this formulation and the preferred composition are as follows:

Preferred Per cent Cellulose nitrate By a slight modification of the procedure already described the anchorage of beads in a deflnite pattern or design on only a portion of the base material may be accomplished. For this pur- Operating range Preferred Per cent Cellulose nitrate 6-12 8 Ethyl acetate 2H0 25 Ethyl alcohol.-- 10-h) 14 Butyl acetate -50 Butyl alcohol 10-20 10 icresyl phosphate 6-12 8 phosphate, such as dibutyl tartrate, acetyl laurins,

dibutyl phthalate, butyl lactate, etc. The use of a cellulose nitrate lacquer is likewise not essential as dispersions of other cellulosic derivatives, such as cellulose acetate may also be employed.

By the process described glass beads and particles may be applied to a base material consisting of coated fabric of various weights and colors. Among these may be specifically mentioned base material having various-decorative designs and printed patterns as well as material prepared from coating compositions containing metallic bronze and aluminum pigments.

The finished material resulting from this prccess is characterized by an anchorage of the glass beads, or particles, which by direct comparison,

'the high degree of optical uniformity resulting from the even application of the adhesive and deposition of the beads. In addition to the realization of a product of improved quality, a further advantage, which results from our method of continuous operation, is the greatly increased rate of production, as compared with the methods commonly employed in the manufacture of beaded surfaces.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments thereof except as defined in the appended claim.

We claim:

A process comprising dipping the surface of a continuously moving strip of embossed sheet material into an adhesive, scraping the moving strip of sheet material to remove the adhesive from the high portions of the design of the embossed material, depositing glass particles over the adhesive in the depressed portions of the design, and drying theadhesive after the sheet material passes the position at which the particles were deposited.

JOHN D. McBURm. EDGAR H. NOLLAU. 

